Adjustable air diffusers



Dec. 20, 1955 c. DAViES 2,727,455

ADJUSTABLE AIR DIFFUSERS Filed Fb. 20, 1952 4 Sheets-Sheet l INVENTOR. CHARLES DAV/ES Dec. 20, 1955 c. DAVIES 2, 6

ADJUSTABLE AIR DIFFUSERS Filed Feb. 20, 1952 4 Sheets-Sheet 2 JNVENTOR. 0mm 5 04 was Dec. 20, 1955 c. DAVIES 2,727,456

ADJUSTABLE AIR DIFFUSERS Filed Feb. 20, 1952 4 Sheets-Sheet 3 .1 q .5. INVENTOR. CHAEL 5 DA 1055 Dec. 20, 1955 Filed Feb. 20, 1952 C. DAVIES ADJUSTABLE AIR DIFFUSERS '0. 46 "'IIIIIIAI IN VEN TOR.

United States Patent 1 2,727,456 ADJUSTABLE AIR DIFFUSERS Charles Davies, New Rochelle, N. Y. Application February 20, 1952, Serial No. 272,627 7 Claims. (Cl. 98-40) My present invention relates generally to air diffusers, and has particular reference to the type of diffuser which is secured to an air duct to spread or distribute the air as it flows outwardly into a room.

A diffuser of this kind is usually intended for installation in a ceiling or wall opening, and for connection to an air duct concealed within the ceiling or wall; but certain phases of my invention are not necessarily restricted to this kind of installation and under certain circumstances the diffuser may be associated with an exposed duct, if desired.

It is a general object of the invention to provide an improved diffuser construction, involving certain new elements and a novel cooperative association of parts, whereby a number of advantages are achieved some of which relate to a simplification of its manufacture, others to improvements in its mode of installation and operation. The new construction also obviates many of the shortcomings and limitations inherent in difiusers heretofore commonly employed.

One of the more particular objects of the invention is to provide a means for expeditiously adjusting the diffuser to vary the volume of the air passing through it, the arrangement being such that it is possible and practical to make such adjustment after the device has been installed and without necessitating its removal. Moreover, the adjustment can be accomplished with usual ease and precision, requiring no special skill, and without alteration of the desired basic difiusion pattern which the installation is intended to establish. By way of example, such a pattern might be the common one according to which the incoming air flows radially from the diifuser and substantially parallel to the wall or ceiling in which it is mounted.

In achieving this result, it is a feature of the invention to employ, as a diffusing element, a spiraliform strip whose convolutions define a set of substantially concentric diffuser vanes inclined at an angle to the axis of the spiral and flaring outwardly into the room. The convolutions are preferably all inclined at the same angle, which is advantageously of the order of 30 to 60 to the spiral axis, and the radial distances between the convolutions are also preferably substantially uniform. The convolutions are of gradually varying radius of curvature so that the diffusing element asla whole is essentially of fiat or pancake shape. When viewed in an axial direction, the inner edge of each convolution slightly overlaps the outer edge of the adjacent one.

In accordance with my invention, this spiraliform element is formed of a single spiral strip whose longitudinal edges are defined by a spiral cut in an initially fiat blank. The spiral along which the cut is made is preferably an Archimedean spiral so that the trip is of substantially uniform width throughout its extent.

The diffusing element is rigidified at its axial and peripheral ends, and a means is provided for adjusting the central region in an axial direction with respect to the peripheral region to efiect corresponding variations in the widths of the spaces between the convolutions. This is achieved by anchoring the peripheral region in relation to the duct to which the diffuser is attached, and by providing interengaging members on the axial and peripheral regions, movable with respect to each other. The member carried by the central or axial region is preferably a rod extending axially and providedat its outer end with a control or actuating knob; and the in-" 2,727,456 Patented Dec. 20, 1955 terengagement of the members is such that they may be held in various selected axial settings of the rod.

The construction of the diffuser is of a kind which lends itself readily (if desired) to the conjoint employment, with the set of substantially concentric diffuser vanes defined by the spiraliform element, of a set of parallel adjustable louver vanes mounted behind the arcuate set. The vanes of the parallel set are preferably individually adjustable and this adjustability, coupled with the adjustability of the conical vanes, afiords a means for altering the air-flow pattern and the air volume in various ways to suit many kinds of special requirements.

Other features of the invention lie in the design of the difiuser as a single structural unit which is easy to handle, simple to install, and readily removable for replacement if desired; in the provision of simple yet efiicient means for stiffening the spiraliform vanes and for guiding them during their adjustments with respect to one another; in a simplified means for separably associating the diffuser unit with a housing mounted in the wall or ceiling opening; and in various expedients employed for making the diffuser attractive in appearance, sturdy and relatively inexpensive in construction, and reliable in its operation.

Ways of achieving these objects and advantages, and such other advantages as may hereinafter appear or be pointed out, are illustrated in the accompanying drawings, in which- Figure 1 is a cross-sectional view of a ceiling installation of a diifuser of the present improved character;

Figure 2 is a bottom view of Figure 1;

Figure 3 is a fragmentary cross-sectional view, on an enlarged scale, showing one of the guide pins in relation to the vanes it passes through;

Figure 4 is a fragmentary cross-sectional view, on an enlarged scale, substantially along the line 4-4 of Figure 1, showing the relative dispositions of the inner ends of the guide pins;

Figure 5 is a top view of Figure 1 with a part of the housing broken away;

Figure 6 is a view similar to Figure 1 showing the vanes in an adjusted relation to enlarge the spaces between them;

Figure 7 is a perspective view, from beneath, of the diffuser as adjusted in Figure 6;

Figure 8 is a similar perspective view of the spiraliform strip by itself;

Figure 9 is a plan view of the flat blank spiraliform element of Figure 8 is formed; v Figure 10 is a detailed cross-sectional view of the mounting and arrangement of the adjusting knob and rod;

: Figure 11 is an enlarged detail similar to the left part of Figure 1 showing a modified securing means for the diffuser unit;

Figure 12 is a fragmentary top view, similar to Figure 5, of a modified diffuser unit employing also a set of parallel louvers; and

Figure 13 is a detail perspective view showing a preferred way of supporting the louvers of Figure 12.

- I have chosen to illustrate the invention in connection with an air duct 20 directed downwardly and positioned above a room ceiling 21 (see Figure l). The ceiling is provided with a suitable opening beneath the duct, and a housing 22 is mounted in this opening. It comprises a rigid circular element, preferably composed of spun aluminum, having an inner cylindrical part 23 secured to the duct 20 by suitable screws 24, an outwardly flaring frusto-conical part 25, and an escutcheon flange 26 at the outer end of the part 25 and lying against the ceiling in well-known fashion.

Y The frusto-conical .part 25 is adapted to accommodate the difiuser unit itself, and a means is provided adjacent of which the o theinner .PG F PIR Y o the e cutc eon flange .26. to:

clamping the difiuser unit in position. In Figures 1-10, the flange 26 is provided at spaced intervals with tabs 27, pivotally secured by. screws or the like, the tabs engaging over the adjacent periphery of the diffuser unit to hold it within-the housing; as;best shown in Figures 1 and 2. In Figure 11, the modified housing 22 is formed with an annular groove 28 adjacent to the inner periphery of the escutcheon flange 26', and a contractible (hence removable) spring ring 29 lies within this groove and bears against the exposed peripheral margin of the diffuser to hold it in place.

The basic element of the diffuser unit is the spiraliformstrip shown in Figure 8. It isrnade of springy metal and originates in a spiral strip 30 (Figure'9) defined by a spiral cut 31 in a flat blank of the metal. Of course, it addition to the cut 31 there are radial cuts 32 which define the inner and outer ends of the strip. The cut 31 is preferably made along an Archimedean spiral whereby the width of the strip is substantially uniform throughout its extent.

By a procedure which need not here be described in detail, the strip 30 of Figure 9 is formed into the spiraliform element shown in Figure 8, the convolutions being of gradually varying curvature to impart an essentially pancake shape to the element as a whole. The convolutions are inclined at an appreciable angle to the axis of the spiral and this angularity is preferably uniform throughout and of the order of 30 to 60, as shown. The longitudinal margins of the strip areangled out of the plane of the strip to provide stifiening flanges 33 and 34,; b st Shown in Figures 1 and 6. The flange 33 on the inneredge of the convoluted strip lies substantially parallel to the spiral axis, while the flange 34 on the outer edge lies substantially transverse to this axis.

The element of Figure 8 is rigidified at both its axial and peripheral ends. I accomplish this at theperipheral end by shaping the peripheral end region 35 (Figure so that it conforms to a circular arc,- as distinguished from a spiral arc, and welding it or otherwise immovably securing it to the adjacent convolution, in the region marked 36. For a neat finish, the stifiening flange 34 may be gradually narrowed toward the end so that there will be as smooth a merger as possible with the flange underlying it in the region 36. Also, if desired, a circular ring 37, having a flat face lying against the flange 34 of the outermost convolution, and a slightly convex face on the outside, may be welded into position on the outside of the diffuser, as best shown in Figure 2. The. ring 37 enhances the rigidity as well as the appearance of the device.

In the axial region of the spiraliform element, the

rigidification is achieved by mounting arigid inverted cup-33, of circular shape, in co-axial relation to the spiralia form element and securing itftangentially within the innermostconvolution, by welding or otherwise. The-cup shaped element 38 may be made of spun steel., It has a cylindrical part 39 1ying against the flange 33 of the innermostconvolution, and an outwardly turned rim 40 lying against the flange 34.

The adjustability of the diffuser stems from a. shifting of the axial region of the spiraliform element, relative to the peripheral region, inthe direction of the axis of the spiral, ThisI achieve by means of interengaging members, and in the preferred construction these members consist of an internally threaded nut or bearing 42 anda rod 43 having threads 46 which are complementary. bearing 42 is carried by and positionally fixed with respect to the, peripheral region of the spiraliforrn element, being rigidly secured to the strap or bar member 44 which extends'in a diarnetric direction at a slight distance behind the outwardly flaring convolutions, and" has down-turned ends welded or otherwise rigidly anchored to the flange" 33, ofJthe outermost convolution. The rod 43' is carried bytheTaxialfregion of the spiraliform" element. It extends 4 in, an axial direction and. terminates in an actuating knob 45. The mounting of these control parts is best shown in Figure 10.

Secured to the base 41 of the cup-shaped element 38 and extending axially outward is a spacer sleeve 47. At its outer end it engages a circular cover element 48 whose rim engages the element38, as shown in Figure 1. The rod 43 is journaled within the sleeve 47, and at the inner end of the latter a cotter pin 49 or its equivalent extends through the rod 43. This pin, and the knob (which is secured to the rod'43 by a set screw 50 or the like prevent longitudinal shifting of the rod 43 relative to the element 38. Thus, by turning the knob 45, and with it the rod 43, the axial region of the spiral is shifted in relation to the bar member 44, hence to the peripheral region of the spiral. This brings about corresponding variations in the spacing between the vanes or convolutions'. The integral nature of the spiral strip causes all the vanes to adjust simultaneously so that the pattern of spacing between the vanes remains the same although the spaces themselves are enlarged or diminished. Thus, where the convolutions are spaced from eachother by a uniform amount throughout the extent of the spiraliform element, this uniformity is substantially maintained at all times. The interengagement of the members 42 and 43 is such that the parts retain their relative positions in any selected setting of the rod 43. I

A cotter pin 49 or the like may be provided, if desired, at the inner end of the rod 43 in order to limit the spreading of the convolutions to the position shown in Figure 6. The adjustability of the parts in the opposite direction can be limited in several ways. I have illustratively shown a construction in which the adjustment is limited by an abutment of the base 41 of the element 38 against the bar member 44, but if desired the parts can be so designed that the upward movement of the rod 43 would be limited by the flange 34 encountering theadjacent convolutions and thus closing the air passages entirely.

In order to guide the flaring louver vanes during these adjustments, I employ guide pins 52 which extend in sub stantially radial directions through the convolutions from the largest to the smallest; For this purpose, the inner flange 33 is provided with sets of aligned openings for these pins. These openings are designated 53 in Figure 3, and they are large enough to permit the pins 52 to pass through them with'ease'. The inner ends of the pins extend through similar openings in the part 39 of the rigidifying ring element 38.

During the adjustmentsof the rod 43, the pins assume various angular inclinations, as is apparent by comparison of Figures 1 and 6. To insure freedom of movement at their inner-ends, the pins are arranged in somewhat tangental relation to the sleeve 47, as best indicated in Figure'4; As will be observed, these inner ends are within the spaceor chamber lying between the parts 38 and 48, andare thus concealed from view. At their outer-ends, the pins are provided withdeformations 54, e. g, by bending the ends transversely; to prevent these ends from passing through the adjacent openings 53. This'anchors the pins in place, since the bent ends 54 are held down by the cylindrical part 23 of the housing 22.

It will be seen that the variations of the spacing between the convolutions can be effected with great ease after the unit has been installed and without requiring its removal. This; permits the volume of air, and the resultant throw of the air, to be controlled with considerable precision, and to be regulated to suit varying I situations without altering the basic pattern of distribution; Moreover, this adjustability effects major economies in manufacturing and installation costs, since a smaller assortment of diffuser sizes is sufficient to comply with a wide varietyof re'c uirements. And when the diffuser is opened to its vvider settings it can handle larger air volumes than ordinary nomadjustame concentric-ring nitfusers' of the'sarne neckarea.

By a slight modification, the usefulness and adaptability of the present diffuser can be even further enhanced. This is illustrated in Figures 12 and 13, in which I have shown how the bar member 44 can serve as a support for a set of parallel louver vanes, thus combining in a single unit the adjustability of a spiraliform diffuser element as hereinbefore described and the capabilities of parallel louvers.

In the modified construction the bar 44 pivotally supports a series of louvers 55 arranged transverse to the bar 44 and in spaced parallel relations. The louvers 55 will vary in length, as shown, to conform to the circular pattern prescribed by the general nature of the diffuser as a whole. The louvers are preferably individually pivotable, and a satisfactory way of achieving this result is shown in Figure 13. Each louver has an edge doubled back, as at 56, to accommodate a pivot pin 57, and at the center of the louver it is cut away, as at 58, so that the pin 57 is exposed. By spot welds 59 or otherwise the pin is rigidly secured to the bar 44. A friction-tight fit of the parts 56 on the pin 57 permits adjustment of the louver vane into various angular positions and serves to retain the vane in whatever selected setting it is pushed into.

The vanes 55 in Figures 12 and 13 have been shown mounted on the rear (inner) face of the bar 44. If desired, they might be arranged, instead, on the forward face of the member 44 so that they would occupy some of the space between the bar 44 and the spiraliform louver vanes. In either case, the adjustments of the louver vanes 55 can be made after the diifuser unit has been installed, by the simple expedient of inserting a screw-driver or similar tool through one or another of the conical diffuser spaces and pressing the rear louvers, one by one, into the angularities desired.

The rear parallel louvers, where used, can serve to control the air flow through the diffuser in a variety of Ways, as will be readily understood. In some cases, the adjustments of the louver vanes might be utilized to equalize the air flow; in other situations it might be desirable to produce a deliberate inequality. Whatever the special requirements of a particular installation might be, the conjoint employment of the individually adjustable parallel louvers, and of the adjustable outwardly flaring louvers of the main diffuser body, permits the air flow pattern and volume to be modified accordingly. Moreover, the ability to shift the dilfuser unit bodily in a rotational direction, thereby shifting the disposition of the bar 44 and of the parallel louvers carried by it, further facilitates these variations.

It will be understood by those skilled in the art that many of the details herein described and illustrated may be modified in a number of respects without necessarily involving a departure from the spirit and scope of the invention as expressed in the appended claims. Except as otherwise characterized, therefore, these details are intended to be merely illustrative.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. In a diffuser, a spiraliform diffusing element all of whose convolutions are inclined at substantially the same oblique angle to the axis of the spiral, said element being formed of a single spiral strip whose longitudinal edges are defined by a spiral cut in an initially flat blank, said out conforming substantially to an Archimedean spiral whereby the width of said strip is substantially uniform throughout its extent, said strip having its longitudinal margins angled out of the plane of the strip to provide stiifcning flanges, the flange along the inner longitudinal margin lying substantially parallel to the axis of the spiral, the flange along the outer longitudinal margin lying substantially transverse to the spiral axis.

2. In a difiuscr, a springy spiraliform diffusing element all of whose convolutions are of substantially the same width and inclined at substantially the same oblique angle to the axis of the spiral, means for rigidifying both the peripheral and the ax al regions of said element, means for adjusting said regions in an axial direction with respect to each other to effect corresponding variations in the spacing between said convolutions, and means constraining the convolutions to maintain the spacing between successive convolutions substantially uniform, said last-named means comprising guide pins extending in substantially radial directions through said convolutions, each pin passing loosely through successive convolutions from the largest to the smallest.

3. In a difiuser, a springy spiraliforrn diffusing element all of whose convolutions are inclined at substantially the same oblique angle to the axis of the spiral, means for rigidifying both the peripheral and the axial regions of said element, said means including a rigid inverted cup of circular shape arranged in co-axial relation to said element and secured tangentially within the innermost convolution thereof, means for anchoring the peripheral region in relation to a Wall or ceiling opening, means for adjusting the axial region in an axial direction to eifect variations in the widths of the spaces between said convolutions, and guide pins extending in substantially radial directions through said convolutions, each pin passing loosely through successive convolutions from the largest to the smallest, said convolutions being provided with sets of aligned openings for said pins, the inner ends of said pins extending through similar openings in said circular rigidifying cup.

4. In a diffuser, the structure set forth in claim 3, said pins being formed at their ends with deformations which cannot pass through the adjacent openings and thus limit the extent to which said convolutions can be spread.

5. In a difiuser, the combination with the structure set forth in claim 3, of a cover engaging said cup to define a chamber Within which the inner ends of said pins are concealed.

6. in a diffuser, a spiraliforrn difiusing element formed of a single spiral strip whose longitudinal edges are de lined by an Archimedean spiral cut in an initially fiat blank, said strip being deformed so that the convolutions of the diffusing element are inclined at a substantially uniform oblique angle to the axis of the spiral, the inner longitudinal margin of said strip being angled out of the plane of the strip to provide a flange lying substantially parallel to the axis of the spiral, means for adjusting the peripheral and axial regions of said difiusing element in an axial direction with respect to each other, and means maintaining the spacing between successive convolutions substantially uniform during said adjustment, said means comprising guide pins extending in substantially radial directions through said convolutions, said flange being provided with sets of radially aligned openings for said pins, each pin passing loosely through the openings of each set.

7. In a difiuser, the combination with the diffusing element defined in claim 1, of a means for rigidifying the axial region of said element comprising a rigid inverted cup of circular shape arranged in co-axial relation to said element and secured tangentially within the innermost convolution thereof, said cup having a cylindrical part lying against the flange along the inner longitudinal margin of said convolution.

References Cited in the file of this patent UNITED STATES PATENTS 1,926,778 Kurth et al Sept. 12, 1933 2,403,291 Kurth July 2, 1946 2,499,856 Gilbert Mar. 7, 1950 2,607,282 Gilbert Aug. 19, 1952 FOREIGN PATENTS 166,131 Switzerland Dec. 31, 1933 396,468 Great Britain Aug. 10, 1933 485,889 Great Britain May 26, 1938 

